R/tots.R

In helophilus/ColsTools: A variety of convenience tools and short-cuts

#' a simple function to add totals to a contingency table (or matrix)
#' of any size. Especially useful for contingency table investigation.
#'
#' @param mat the name of the matrix, either labelled or not.
#'
#' @return a matrix with an additional row and column giving totals.
#' @examples
#' X = matrix(1:12,3)
#' tots(X)


tots=function(mat){
  NC = ncol(mat); NR = nrow(mat)
  MAT=matrix(,NR+1,NC+1)
  MAT[1:NR,1:NC]=mat
  if(sum(nchar(dimnames(mat)))==0){
    colnames(mat)=rep("",NC)
    rownames(mat)=rep("",NR)
  }
  dimnames(MAT)=list(c(dimnames(mat)[[1]],"total"),
                     c(dimnames(mat)[[2]],"total"))
  names(dimnames(MAT))=names(dimnames(mat))
  MAT[1:NR,NC+1]=rowSums(mat)
  MAT[NR+1,1:(NC+1)]=colSums(MAT[-(NR+1),])
  return(MAT)
}